Your theory does not hold up. Yes Photoshop has many limits you can not exceed. For example Photoshop only supports up to 53 Alpha channels try to create the 54 Alpha channel and Photoshop will let you know you can't. Photoshop supports something like up to 8,000 layers you can not exceed that try and Photoshop will let you known that you can not make more layers.. A PSD file has a file size limit you can not exceed 4GB. If you layered document would exceed 4GB in file size Photoshop would inform you that you can not save the document in PSD file for it would require more then 4GB of data. You would at this point save in PSB file format. You can not exceed limits. Limits are not hidden they also may not be published however if you try to exceed a limit Photoshop will let you know.
Read what the message states. There is a problem reading some layer data. There is either corrupt data a file error a layer data did not write correctly or was written correctly by a newer version Photoshop which has some option not supported in this release of Photoshop. So Photoshop can not correctly make that layer in the document its trying to open. Photoshop is giving you the option to either have it use a raster layer for the layer it can not process or or just open a single composite layer for the entire image. So you don't completely loose your image.